The objective of this research is to improve the efficiency of kidney dialysis. Efficiency of mass transfer devices is determined by clearance rate across the membrane. One of the primary restrictions to clearance is the boundary layer condition at the membrane surface which exists in either tube or channel. The aim is to increase efficiency by disrupting the boundary layer, thus altering clearance of common metabolites such as sodium chloride, urea, creatinine and vitamin B12. Proposed, is an "active" mixing to increase efficiency by utilizing low power ultrasonic energy to agitate blood and break up boundary layers in the blood envelope, allowing more plasma and formed elements to contact membrane on each pass. An ultrasonic transducer is coupled to parallel plate and hollow fiber dialyzers and then excited with varying power levels in specific frequency ranges. Improved efficiency is determined by comparison of assay results of blood substance clearances for ultrasonic versus non- ultrasonic (control) dialysis. Additionally, cellular damage is monitored by comparing hemolysis values of ultrasonic versus control dialysis. Coupling ultrasonic transducers to dialyzers should improve patient management and reduce costs by diminishing the duration of kidney dialysis treatments. PROPOSED COMMERCIAL APPLICATION: This research tests the ability of ultrasonic transduction to increase the efficiency of mass transfer devices. By coupling ultrasonic transducers to dialyzers an improvement of patient management and cost reduction may be realized by diminishing the duration of kidney dialysis treatments.